1. Field of the Invention
The present invention relates generally to the field of cancer treatment. More specifically, the present invention relates to a method of same day diagnosis and treatment for cancer such as breast cancer.
2. Description of the Related Art
One in nine American women will develop breast cancer in their lifetime. It is the leading cause of cancer deaths in women 40–55 years of age and the second leading cause of cancer deaths in women overall. Breast cancer will be diagnosed in approximately one in eight women in their lifetime, and one in 30 will die of this disease. Breast cancer does occur in males but is much less common. Biopsy requests stem from a screening process generally performed via a physical examination (palpable) and/or mammogram (non-palpable). A biopsy is indicated if suspicious tissue is detected. Five out of six biopsies performed return benign indications.
It is desirable and often necessary to perform procedures of detecting, sampling, and testing lesions and other abnormalities in the tissues of humans and other animals for pre-malignant condition. This is particularly important in the diagnosis and treatment of patients with cancerous tumors. Typically, in the case of cancer, when a physician establish by means of known procedures (i.e. palpation, x-ray, MRI, or ultrasound imaging) that suspicious circumstances exist, a biopsy is performed to determine whether the cells are cancerous.
Biopsy may be an open or percutaneous technique. Open biopsy removes the entire mass (excisional biopsy) or a part of the mass (incisional biopsy). Percutaneous biopsy on the other hand is usually done with a needle-like instrument and may be either a fine needle aspiration (FNA) or a core biopsy. In fine needle aspiration biopsy, very small needles are used to obtain individual cells or clusters of cells for cytologic examination. The cells may be prepared such as in a Papanicolaou (Pap) smear. In core biopsy, as the term suggests, a core or fragment of tissue is obtained for histologic examination, which may be done via a frozen section or paraffin section. The chief difference between fine needle aspiration and core biopsy is the size of the actual tissue core taken. An imaging system having spectroscopic capabilities, such as the stereotactic guidance system described in U.S. Pat. No. 5,240,011 is employed to guide the extraction instrument to the lesion.
Depending on the procedure being performed, the suspicious lesion may be partially or completely removed. Visibility of the lesion by the imaging system may be hampered because of the distortion created by the extraction process itself as well as associated bleeding in the surrounding tissues. Although the lesion is removed and all fluids are continuously aspirated from the extraction site, it is likely that the process will “cloud” the lesion, thus impairing exact recognition of its margins. This makes it difficult to ensure that the entire lesion will be removed.
Often, the lesion is merely a calcification derived from dead abnormal tissue which may be cancerous or precancerous, and it is desirable to remove only a sample of the lesion rather than the entire lesion. This is because such a lesion actually serves to mark or define the location of adjacent abnormal tissue, so the physician does not wish to remove the entire lesion and thereby lose a critical means for later relocating the affected tissue. One of the benefits to the patient from core biopsy is that the mass of the tissue taken is small. However, oftentimes, either inadvertently or because the lesion is too small, the entire lesion is removed for evaluation, even though it is desirable to remove only a portion. Thus, if subsequent analysis indicates the tissue to be malignant, it is difficult for the physician to determine the precise location of the lesion in order to perform necessary additional procedures on adjacent potentially cancerous tissue. Malignant tissue requires removal, days or weeks later, of tissue around the immediate site of the original biopsy. Additionally, even if the lesion is found to be benign, there will be no evidence of its location during future examinations to mark the location of the previously removed calcification so that the affected tissue may be carefully monitored for future reoccurrence.
A number of procedures and devices for marking and locating particular tissue locations are known in the prior art. For example, location wire guides, such as that described in U.S. Pat. No. 5,221,269 are well known for locating lesions, particularly in the breast. The device comprises a tubular introducer needle and an attached wire guide which has at its distal end a helical coil configuration for locking into position about the targeted lesion. The needle is introduced onto the breast and guided to the lesion site using an imaging system of a known type, for example, x-ray, ultrasound or magnetic resonance imaging (MRI), at which time the helical coil at the distal end is deployed about the lesion. The needle may then be removed from the wire guide which remains in a locked position distally about the lesion for guiding a surgeon down the wire to the lesion site during subsequent surgery. While such a location system is effective, it is obviously intended and designed to be only temporary, and is removed once the surgery or other procedure has been completed.
Other devices are known for marking external regions of a patient's skin. For example, U.S. Pat. No. 5,192,270 to Carswell, Jr. discloses a syringe which dispenses a colorant to give a visual indication on the surface of the point at which an injection has or will be given. Similarly, U.S. Pat. No. 5,147,307 to Gluck discloses a device which has patterning elements for impressing a temporary mark in a patients skin for guiding the location of an injection or the like. It is also known to tape or otherwise adhere a small metallic marker, e.g. a 3 millimeter diameter lead sphere, on the skin of a human breast in order to delineate the location of skin calcifications. Obviously, however, none of these approaches are useful for marking and delineating internal tissue abnormalities, such as lesions or tumors.
A method of identifying and treating abnormal neoplastic tissue or pathogens within the body is described in U.S. Pat. No. 4,649,151 to Doughety et al. In this method, a tumor-selective photosensitizing drug is introduced into a patient's body, where it is cleared from normal tissue faster than it is cleared from abnormal tissue. After the drug clears normal tissue but before it has cleared abnormal neoplastic tissue, the abnormal neoplastic tissue may be located by the luminescence of the drug within the abnormal tissue. The fluorescence may be observed with low intensity light, some of which is within the drug's absorbency spectrum. Once detected, the tissue may be destroyed by further application of higher intensity light having a frequency within the absorbency spectrum of the drug. Of course, this method also is only a temporary means for marking the abnormal tissue. Additionally, once the abnormal tissue has been destroyed during treatment, the marker is destroyed as well.
It is also known to employ biocompatible dyes or stains to mark breast lesions. First, a syringe containing the colorant is guided to a detected lesion by an imaging system. Later, during the extraction procedure, the surgeon harvests a tissue sample from the stained tissue. However, while such staining techniques can be effective, it is difficult to precisely localize the stain. Also, the stains are difficult to detect flouoroscopically and may not always be permanent.
Thus, the prior art is deficient in a treatment system for breast cancer that remove the tumor and ablate the margin of the tumor. The present invention fulfills this long-standing need and desire in the art.